Sweet steviol glycoside compounds are present in small concentrations and can be extracted from plant materials, particularly the leaves of the Stevia rebaudiana Bertoni plant. A crude stevia extract typically comprises stevioside, steviolbioside, several rebaudiosides, including rebaudioside A, rebaudioside B, rebaudioside C, rebaudioside D, and rebaudioside E, and dulcoside compounds. For convenience, the rebaudiosides may be referred to here as Reb A, Reb B, Reb C, etc.
Of the Rebaudiosides, Reb A is commonly used as sweetener in beverage applications, but has off-taste issues. Reb D has a better sugar character and more desirable taste than Reb A, but Reb D is difficult to use in food products because of its low solubility in water at room temperature. For instance, Reb D needs to be heated to near boiling water temperature for 2 hours in order to achieve complete dissolution at 0.8% concentration. At most only 300 to 450 ppm can be solubilized in water at 23° C.
Due to this low solubility, if when Reb D was is used in beverages, for example, it was needs to be combined with other sweeteners having good solubility that are more soluble in water. There is business interest now into developing sweetener compositions higher in Reb D content, e.g., sweetener compositions having a sweetening amount of Reb D (i.e., an amount of Reb D that perceptibly contributes to the total sweetness provided by the sweetener), for example, sweeteners in which Reb D is the primary sweetener. Such development is impeded, in part by the lack of low solubility in water of the Reb D, thus making it difficult to use in beverages, for example. It would be advantageous, therefore, to develop improved methods to enhance solubility of Reb D in water at room temperature (20-25° C.).
Traditional processes for making beverages manufacturing process involves an intermediate concentrated syrup step require a 6 folds concentration of ingredients in a concentrate or syrup. This syrup is then diluted by 5 folds of with water. This works fine if all syrup ingredients are soluble in water to the extent of 6 folds of the level in the finished beverage. Reb D is not very soluble (about 300-450 ppm) and cannot be provided in a syrup or concentrate in amounts sufficient enough to provide a sweetened beverage.
Accordingly, it is an object of some aspects of the present invention to provide improved methods to enhance the solubility of Reb D in water. Additional objects and advantages of all or certain embodiments of the systems and methods disclosed here will be apparent to those skilled in the art given the benefit of the following disclosure and discussion of certain exemplary embodiments.